1) Field of the Invention
The present invention relates to a separator which diverts selected components of a fluid stream out of the main stream using magnetic force fields.
2) Prior Art
Magnetic force fields can be created by electric currents and are known a magnetic fields. In magnetic separators, field gradients are produced which are changes in field strength with respect to position in the field volume. Magnetic field gradients produce forces on molecules or particles which have a non zero magnetic susceptibility.
Previously patented separators using magnetic fields such as magnetic separators use a high strength magnetic field to produce magnetic gradients in the fluid flow. Magnetic materials in the fluid interact with the magnetic gradients because of the magnetic forces between them.
The intermittent type of magnetic separators such as the Kolm type, see U.S. Pat. No. 3,676,337, have the magnetic gradients randomly distributed throughout the volume of fluid flow and rely on the magnetic forces to embed the magnetic materials in the magnetic gradient areas. They must be turned off and periodically flushed to clean the magnetic materials away.
To overcome the requirement of periodically flushing, several continuous magnetic separators have been proposed.
Kelland in U.S. Pat. No. 4,261,815, discloses a separator apparatus in which a grid of fine ferromagnetic wires are arranged parallel to the flow of the fluid to be separated and a strong magnetic field is produced perpendicular to the wires and flow. The wires distort the magnetic field and result in a magnetic gradient around the wires which concentrates magnetic materials on opposite sides along each wires axis. As the wires near the end of the magnetic field there is a grid matrix for separation of the flows from each wire. This results in the need for small openings for each wire, which can become clogged and are difficult to fabricate.
In U.S. Pat. No. 5,169,006 I previously patented a continuous magnetic separator which employs rods comprised of alternating sections of nonmagnetic and ferromagnetic materials. This invention is an improvement on that patent because this invention is more efficient because the field gradients are continuous across the separation region.